Detection device and display device with detection function

ABSTRACT

[Problem] To prevent detachment of overcoat layer which covers at least a part of a terminal formed on a substrate. 
     [Measure to solve the problem] According to one embodiment, a detection device includes a substrate, detection electrode, terminal formed of a metal material, lead, coating layer, conductive adhesion layer, and circuit board. The lead connects the electrode and the terminal. The coating layer covers the electrode and the lead, and partly covers the terminal. The adhesion layer covers a part of the terminal exposed from the coating layer and covers a part of the coating layer. The circuit board is connected to the terminal with the adhesion layer interposed therebetween. At least in an overlapping area where the conductive adhesion layer covers the coating layer, the metal material that forms the terminal includes a shape that the metal material is partly removed.

TECHNICAL FIELD

The embodiments of this invention described herein relate to a detectiondevice and a display device with a detection function.

BACKGROUND ART

Detection devices configured to detect an object touching or approachinga display area, and display devices with such a detection function arecommercially used.

Such detection devices and display devices include, for example, adetection electrode for detecting an object, a terminal used forconnection with a flexible printed circuit, and a lead configured toelectrically connect the detection electrode and the terminal are formedon a substrate. The flexible printed circuit is electrically connectedto the terminal via a conductive adhesion layer such as an anisotropyconductive layer.

If the lead, terminal, and detection electrode are formed of metalmaterials, advantages such as low resistivity can be achieved; however,metal materials are easily damaged and easily affected by water ascompared to an indium tin oxide (ITO) or the like. In consideration ofthis point, the detection electrode, lead, and terminal must be partlycovered with an overcoat layer of organic material, for example, toprevent damage and corrosion of the metal material.

Generally, adhesion of metal materials and an overcoat layer is weakerthan adhesion of, for example, a glass substrate and an overcoat layer.Therefore, detachment of the overcoat layer may occur in detectiondevices with an overcoat layer or display devices with detectionfunction.

PRIOR ART REFERENCES Patent Documents

[Patent Document 1] JP-2008-112911-A

[Patent Document 2] JP-2004-6632-A

SUMMARY OF INVENTION Problem that the Invention to Solve

An embodiment of the present application aims preventing detachment ofovercoat layer which covers at least a part of a terminal formed on asubstrate.

Measures to Solve the Problem

According to one embodiment of a detection device, the detection deviceincludes a substrate, detection electrode, terminal, lead, coatinglayer, conductive adhesion layer, and circuit board. The detectionelectrode is formed on a main surface of the substrate. The terminal isformed of a metal material on the main surface. The lead is formed onthe main surface and electrically connects the detection electrode andthe terminal. The coating layer covers the detection electrode and thelead, and partly covers the terminal. The conductive adhesion layercovers a part of the terminal exposed from the coating layer and coversa part of the coating layer. The circuit board is electrically connectedto the terminal with the conductive adhesion layer interposedtherebetween. At least in an overlapping area where the conductiveadhesion layer covers the coating layer, the metal material that formsthe terminal includes a shape that the metal material is partly removed.

According to one embodiment of a display device with a detectionfunction, the display device includes a display panel, a detectionelectrode, a terminal, a lead, a coating layer, a conductive adhesionlayer, a circuit board and a detection circuit. The display panelincludes a display element, a plurality of first electrodes disposed inrespective pixels in a display area, and second electrodes opposed tothe first electrodes, the display panel configured to display an imagein the display area by selectively applying a voltage between the firstelectrodes and the second electrodes to drive the display element. Thedetection electrode is formed on an outer surface of the display panel.The terminal is formed of a metal material on the outer surface of thedisplay panel. The lead is formed on the outer surface of the displaypanel and electrically connects the detection electrode, the lead andthe terminal. The coating layer covers the detection electrode, thelead, and a part of the terminal. The conductive adhesion layer coveringa part of the terminal exposed from the coating layer and covers a partof the coating layer. The circuit board is electrically connected to theterminal with the conductive adhesion layer interposed therebetween. Thedetection circuit is configured to detect the object based on a secondsignal output from the detection electrode to the circuit board throughthe lead and the terminal when a first signal for detection of theobject is supplied to the second electrode. Further, at least in anoverlapping area where the conductive adhesion layer covers the coatinglayer, the terminal has a shape that the metal material of the terminalis partially removed.

BRIEF EXPLANATION OF DRAWINGS

FIG. 1 is a perspective view which schematically shows the structure ofa liquid crystal display device of an embodiment.

FIG. 2 is a cross-sectional view which schematically shows a liquidcrystal display panel of the liquid crystal display device, and elementsprovided with the main surface of the liquid crystal display panel.

FIG. 3 shows a sensor of the liquid crystal display device.

FIG. 4 is a plan view which schematically shows an example of elementsprovided with a main surface of an insulating substrate of the liquidcrystal display panel.

FIG. 5 shows a joint part of terminals and a flexible printed circuitformed on the main surface in an enlarged manner.

FIG. 6 schematically shows a cross-sectional view taken along line VI-VIof FIG. 5.

FIG. 7 shows an example of an end shape irregularity in an overcoatlayer formed on the main surface.

FIG. 8 shows an example of the shape of the terminal.

FIG. 9 shows a shape of the terminal of the first example.

FIG. 10 shows a shape of the terminal of the second example.

FIG. 11 shows a shape of the terminal of the third example.

FIG. 12 shows a shape of the terminal of the fourth example.

FIG. 13 shows a shape of the terminal of the fifth example.

FIG. 14 shows a shape of the terminal of the sixth example.

FIG. 15 shows an outline of the assessment of a width of a line of theterminal of the first example.

FIG. 16 is a table showing a result of the measurement of a length ofthe overcoat layer projecting on the line of the terminal of the firstexample.

FIG. 17 shows an outline of the assessment of a width of a line of theterminal of the fourth example.

FIG. 18 is a table showing a result of the measurement of a length ofthe overcoat layer projecting on the line of the terminal of the fourthexample.

EMBODIMENTS TO IMPLEMENT THE INVENTION

An embodiment will be described with reference to accompanying drawings.Note that the disclosure is presented for the sake of exemplification,and any modification and variation conceived within the scope and spiritof the invention by a person having ordinary skill in the art arenaturally encompassed in the scope of invention of the presentapplication. Furthermore, the width, thickness, shape, and the like ofeach element are depicted schematically in the Figures as compared toactual embodiments for the sake of simpler explanation, and they are notto limit the interpretation of the invention of the present application.Furthermore, in the description and figures of the present application,structural elements having the same or similar functions will bereferred to by the same reference numbers and detailed explanations ofthem that are considered redundant may be omitted.

In the present embodiment, a liquid crystal display device withdetection function is disclosed as an example of the display device. Forexample, the liquid crystal display device can be used in variousdevices such as smartphones, tablet terminals, mobile phone terminals,personal computers, TVs, in-car devices, and game consoles. Note that adisplay panel of the display device with detection function is notlimited to a liquid crystal display panel and may be display panelsincluding different kind of display elements such as a self-luminousdisplay panel including organic electroluminescent display elements, anelectronic paper display panel including electrophoresis elements andthe like.

FIG. 1 is a perspective view which schematically shows the structure ofa liquid crystal display device DSP of the present embodiment. Asdepicted, the liquid crystal display device DSP includes, for example,an active matrix type liquid crystal display panel PNL, a driver IC chipIC1 which drives the liquid crystal display panel PNL, a capacitivesensor SE, a driver IC chip IC2 which drives the sensor SE, a backlightunit BL which illuminates the liquid crystal display panel PNL, acontrol module CM, and flexible printed circuits FPC1, FPC2, and FPC3.

The sensor SE includes a plurality of detection electrodes Rx formed onthe display surface of the liquid crystal display panel PNL.

Driver IC chip IC1 is mounted on the liquid crystal display panel PNL.Flexible printed circuit FPC1 connects the liquid crystal display panelPNL and the control module CM. Flexible printed circuit FPC2 connects atleast a partial element of the sensor SE and the control module CM.Driver IC chip IC2 is mounted on the flexible printed circuit FPC2. Theflexible printed circuit FPC3 connects the backlight unit BL and thecontrol module CM.

The liquid crystal display panel PNL includes a first substrate SUB1, asecond substrate SUB2 opposed to the first substrate SUB1, and a liquidcrystal layer (the liquid crystal layer LC described later) held betweenthe first substrate SUB1 and the second substrate SUB2.

The liquid crystal display panel PNL includes a display area DA by whichimages are displayed. In the example of FIG. 1, detection electrodes Rxare provided with the display area DA. The detection electrodes Rxextend in a first direction X and arranged along a second direction Ywhich crosses the first direction X. For example, the first direction Xand the second direction Y are orthogonal to each other. The first andsecond directions may cross at any angle other than right angles.

The backlight unit BL is arranged at the rear surface side of the firstsubstrate SUB1. The backlight unit BL can be achieved in various forms.For example, the backlight unit BL includes a light guide plate opposedto the first substrate SUB1 and a light source such as a light emittingdiode (LED) arranged along the edges of the light guide plate.

FIG. 2 is a cross-sectional view which schematically shows the liquidcrystal display panel PNL and elements provided with the main surface ofthe liquid crystal display panel PNL. The liquid crystal display panelPNL includes unit pixels PX (unit pixel area). One unit pixel PX is aminimum unit of a color image displayed on the display area DA.

FIG. 2 shows an example of unit pixel PX in which subpixels PXR, PXG andPXB (subpixel areas) corresponding colors of red, green and blue,respectively, are arranged in the first direction X. In the display areaDA, a large number of unit pixels PX are arranged in a matrix. Note thatthe layout of the subpixels PXR, PXG and PXB of the unit pixel PX is notlimited to the example of FIG. 2, and the three subpixels PXR, PXG andPXB are not necessarily arranged in the same direction. Furthermore,unit pixel PX may include a subpixel of a different color other thanred, green and blue, that is, a white subpixel or the like.

As described above, the liquid crystal display panel PNL includes thefirst substrate SUB1, the second substrate SUB2 opposed to the firstsubstrate SUB1, and the liquid crystal layer LC held between the firstsubstrate SUB1 and the second substrate SUB2.

The first substrate SUB1 includes a first insulating substrate 10 whichis a light transmissive glass substrate, light transmissive resinsubstrate, or the like. The first insulating substrate 10 has a firstmain surface 10A facing the second substrate SUB2 and a second mainsurface 10B which is opposite to the first main surface 10A.

Furthermore, the first substrate SUB1 includes a first insulating layer11 covering the first main surface 10A of the first insulating substrate10, a common electrode CE disposed on the first insulating layer 11, anda second insulating layer 12 covering the common electrode CE.

Furthermore, the first substrate SUB1 includes pixel electrodes PER, PEGand PEB corresponding to the subpixels PXR, PXG and PXB, respectively,and a first alignment layer AL1 which covers the pixel electrodes PER,PEG and PEB and the second insulating layer 12 and contacts the liquidcrystal layer LC. The common electrode CE and the pixel electrodes PER,PEG and PEB are opposed to each other with the second insulating layer12 interposed therebetween. In the example of FIG. 2, each of the pixelelectrodes PER, PEG and PEB has a slit PSL.

The common electrode CE and the pixel electrodes PER, PEG and PEB areformed of a transparent conductive material such as indium tin oxide(ITO) or indium zinc oxide (IZO).

On the other hand, the second substrate SUB2 includes a secondinsulating substrate 20 which is a light transmissive glass substrate,light transmissive resin substrate, or the like. The second insulatingsubstrate 20 has a first main surface 20A facing the first substrateSUB1, and a second main surface 20B which is opposite to the first mainsurface 20A. Furthermore, the second substrate SUB2 includes colorfilters CFR, CFG and CFB provided with the first main surface 20A of thesecond insulating substrate 20, and black matrix 21.

Color filter CFR is a red filter which is formed of a red resin materialand disposed to correspond to the red subpixel PXR. Color filter CFG isa green filter which is formed of a green resin material and disposed tocorrespond to the green subpixel PXG. Color filter CFB is a blue filterwhich is formed of a blue resin material and disposed to correspond tothe blue subpixel PXB.

The black matrix 21 defines subpixels PXR, PXG and PXB. Each boundary ofthe color filters CFR CFG, and CFB is placed on the black matrix 21.

Furthermore, the second substrate SUB2 includes a third insulating layer22 covering the color filters CFR, CFG, and CFB and the black matrix 21,and the second alignment layer AL2 which covers the third insulatinglayer 22 and contacts the liquid crystal layer LC.

In the example of FIG. 2, a first polarizing plate PL1 and a firstadhesive layer GL1 are provided with the second main surface 10B of thefirst insulating substrate 10. The first polarizing plate PL1 is adheredto the second main surface 10B by the first adhesive layer GL1.

Furthermore, in the example of FIG. 2, the detection electrodes Rx, theovercoat layer OC (protective film), the second polarizing plate PL2,and the second adhesive layer GL2 are provided with the second mainsurface 20B of the second insulating substrate 20. Note thatphase-difference plates may be disposed between the first polarizingplate PL1 and the first insulating substrate 10, and between the secondpolarizing plate PL2 and the second insulating substrate 20.

The overcoat layer OC covers the detection electrodes Rx. The overcoatlayer OC may be formed of an organic material such as polyimide, acrylicresin, and epoxy resin.

The second polarizing plate PL2 is adhered to the overcoat layer OC bythe second adhesive layer GL2. The first polarizing plate PL1 has afirst axis of polarization and the second polarizing plate PL2 has asecond axis of polarization, and these axes of polarization (absorptionaxes) are orthogonal to each other on the X-Y plane as in acrossed-Nicol state.

Note that the structure of FIG. 2 is applicable to, for example, aliquid crystal display panel PNL of transverse field mode which uses atransverse field substantially parallel to the main surface of thesubstrate in switching of liquid crystal molecules. However, the mode ofthe liquid crystal display panel PNL is not limited to the transversefield mode, and may be a vertical field mode, which uses a verticalfield normal to the substrate surface in switching of liquid crystalmolecules, such as twisted nematic (TN) mode and vertically aligned (VA)mode.

The sensor SE is composed of, for example, detection electrodes Rx andcommon electrodes CE. In that case, the common electrodes CE function aselectrodes for display and also functions as driver electrodes forsensing. The structure and the operation of the sensor SE will beexplained below.

FIG. 3 shows a sensor SE in a schematic plan-view of a positionalrelationship of detection electrodes Rx and common electrodes CE. In theexample depicted, a display area DA is a rectangle having short sidesparallel to the first direction X, and long sides parallel to the seconddirection Y. In the display area DA, detection electrodes Rx extend inthe first direction X in stripes and are arranged along the seconddirection Y at certain intervals, and common electrodes CE extend in thesecond direction Y in stripes and are arranged along the first directionX at certain intervals.

The detection electrodes Rx are electrically connected to a detectioncircuit RC. The detection circuit RC is stored in, for example, thedriver IC chip IC2. The detection circuit RC may be provided with thecontrol module CM, or the like.

The common electrode CE is electrically connected to a common electrodedriver circuit CD. The common electrode driver circuit CD is formed onthe first substrate SUB1 outside the display area DA, for example.

The common electrode driver circuit CD selectively supplies commondriving signals used for driving subpixels of each unit pixel PX andsensor driving signals used for driving the sensor SE to the commonelectrodes CE. For example, the common electrode driver circuit CDsequentially supplies common driving signals to each common electrode CEduring a display period in which images are displayed on the displayarea DA and sensor driving signals to each common electrode CE during asensing period in which an object contacting or approaching the displayarea DA is detected.

When the sensor driving signals are supplied, a first capacitance isproduced between the common electrodes CE and the detection electrodesRx. When a conductive object exists in the proximity of the display areaDA, a second capacitance is produced between the object and thedetection electrodes Rx. The second capacitance changes the firstcapacitance between the detection electrodes Rx in the proximity of theobject and the common electrodes CE. Therefore, sensor output signalsobtained from the detection electrodes Rx in the proximity of the objectand sensor output signals obtained from the other part of the detectionelectrodes Rx show different values.

The detection circuit RC detects an object contacting or approaching thedisplay area DA based on a change in the sensor output signals.Furthermore, the detection circuit RC can detect a position of contactor approach of an object within the display area DA.

Now, elements provided with the second main surface 20B of the secondinsulating substrate 20 will be explained in detail. Note that thesecond main surface 20B corresponds to one of the main surfaces of theliquid crystal display panel PNL including the display area DA.

FIG. 4 is a plan view which schematically shows the elements providedwith the second main surface 20B of the second insulating substrate 20.In the example depicted, each detection electrode Rx includes aplurality of detection lines LN1 and a connection line LN2 connectingthe detection lines LN1. The detection lines LN1 connected by theconnection line LN2 each extend zigzag in the first direction X drawinga wave form (specifically, a triangular wave form) and arranged alongthe second direction Y at certain intervals.

Note that the structure of the detection electrodes Rx is not limited tothe example of FIG. 4. For example, the detection electrodes Rx may beformed of metal lines crossed in a mesh-like manner. Furthermore,electrically floating dummy electrodes may be provided between detectionelectrodes Rx. Such a dummy electrode may be, for example, a detectionline cut at an arbitral position and formed in a similar shape to thedetection electrodes Rx.

A frame area FA is provided with the second main surface 20B to surroundthe display area DA from the outside thereof. In the frame area FA, aplurality of first terminals T1 and a plurality of leads LN3 used forone-to-one electrical connection between the detection electrodes Rx andthe first terminals T1 are formed. In the example of FIG. 4, the firstterminals T1 are arranged along the first direction X at certainintervals. Each first terminal T1 is electrically connected to theflexible printed circuit FPC2. Note that first terminal T1 may bereferred to as pad.

The detection lines LN1, connection lines LN2, the leads LN3 and thefirst terminals T1 are, for example, integrally formed on the secondmain surface 20B, of the same metal material, and through the samemanufacturing step. The metal material may be, for example, aluminum(Al), molybdenum (Mo), or an alloy containing either Al or Mo.Alternately, the detection lines LN1, the connection lines LN2, theleads LN3, and the first terminals T1 may be formed as a layeredstructure of a plurality of metal materials. For example, a layeredstructure of the detection lines LN1, the connection lines LN2, theleads LN3, and the first terminals T1 may be composed of six layersincluding an aluminum alloy interposed between molybdenum alloybarrier-metals and three films having different refractive indicesplaced on the alloys. Note that the number of the layers of the metalmaterials is not limited to six and may be reduced or increased.

The second polarizing plate PL2, second adhesive layer GL2, and overcoatlayer OC are each formed in a rectangular shape covering the displayarea DA. In the example of FIG. 4, the second polarizing plate PL2 andthe second adhesive layer GL2 are formed in the same shape and arrangedon the second main surface 20B such that their peripheries match witheach other. The periphery of the overcoat layer OC substantially matcheswith the periphery of the second insulating substrate 20 except for theside R1 where the first terminals T1 are provided with.

In the example of FIG. 4, the overcoat layer OC covers not only thedisplay area DA but also the substantial part of the frame area FA. Theovercoat layer OC covers the detection lines LN1 and the connectionlines LN2 of the detection electrodes Rx, and the leads LN3.Furthermore, the overcoat layer OC covers a part of each first terminalT1. That is, each first terminal T1 is disposed on the second mainsurface 20B along one side (side R1) of the overcoat layer OC.

FIG. 5 shows the proximity of joint part of the first terminals T1 andthe flexible printed circuit FPC2 in an enlarged manner. In the exampledepicted, eight first terminals T1 are arranged along the firstdirection X at certain intervals. The first terminals T1 extend alongthe second direction Y in stripes. Each first terminal T1 is connectedto a lead LN3.

Alignment marks M are arranged in the proximity of the first terminalsT1 as marks for positioning of the flexible printed circuit FPC2 in itsimplementation process. In the example of FIG. 5, two pairs of L-shapedalignment marks M are arranged in the proximity of the two outermostones of the first terminals T1, respectively, with a certain gaptherebetween along the first direction X. The alignment marks M areformed on the second main surface 20B, of the same material and throughthe same manufacturing process as those of the detection lines LM1, theconnection lines LN2, the leads LN3, and the first terminals T1.

The overcoat layer OC has a projection R1 a projecting from the side R1along the second direction Y. The projection R1 a extends to theproximity of the middle of the first terminals T1 to partly cover thefirst terminals T1. In the present embodiment, the projection R1 a doesnot cover any alignment mark M.

The flexible printed circuit FPC2 includes a plurality of secondterminals T2 electrically connected to the first terminals T1,respectively. The second terminals T2 are arranged along the firstdirection X at the same intervals of the first terminals T1, and extendin the second direction Y in stripes. An anisotropy conductive layer ACFis disposed between the flexible printed circuit FPC2 and the firstterminals T1. The anisotropy conduction layer ACF is an example of aconductive adhesion layer. Each second terminal T2 faces the firstterminal T1 corresponding to it with the anisotropy conductive layer ACFinterposed therebetween. The anisotropy conductive layer ACF adheres theflexible printed circuit FPC2, the first terminals T1, and second mainsurface 20B, and electrically connects each pair of the first terminalT1 and the second terminal T2 opposed to each other.

The anisotropy conductive layer ACF partly covers the projection R1 a ofthe overcoat layer OC. In the following description, an area of theovercoat layer OC covered by the anisotropy conductive layer ACF isreferred to as overlap area OL. Furthermore, an area of the second mainsurface 20B which is covered by the overcoat layer OC and does notoverlap the anisotropy conductive layer ACF in plan view is referred toas first area A1, and an area of the second main surface 20B which iscovered by the anisotropy conductive layer ACF and does not overlap theovercoat layer OC in plan view is referred to as second area A2. In theexample of FIG. 5, the overlap area OL has a substantially constantwidth in the second direction Y and extends in the first direction X.The area and position opposed to the overlap area OL are substantiallythe same in the first terminals T1.

FIG. 6 schematically shows a cross-sectional view taken along the lineVI-VI of FIG. 5. The first terminals T1 formed on the second mainsurface 20B of the second insulating substrate 20 are covered by theovercoat layer OC at the display area DA side (left side in the figure)while their tips (right side in the figure) are exposed from theovercoat layer OC. The parts of the first terminals T1 exposed from theovercoat layer OC are opposed to the second terminals T2 of the flexibleprinted circuit FPC2 with the anisotropy conductive layer ACF interposedtherebetween.

The anisotropy conductive layer ACF contains a large number ofanisotropy conductive particles R. The anisotropy conductive particle Ris, for example, a sphere of a metal material covered with an insulatinglayer. When the flexible printed circuit FPC2 is applied on this layeredstructure, the flexible printed circuit FPC2 is initially placed on theanisotropy conductive layer ACF and then thermo-pressed thereon. In thisprocess, the anisotropy conductive particles R are crashed between thefirst terminals T1 and the second terminals T2, and the internal metalmaterials of the particles R are exposed through their insulatinglayers. Accordingly, the first terminals T1 and the second terminals T2are electrically conducted through the crashed particles R. Note that,in a plan view, the non-conduction between the first terminals T1 andsecond terminals T2 arranged alongside, the non-conduction between firstterminals T1, and the non-conduction between second terminals T2 are allmaintained.

In general, the adhesion between the first terminals T1 formed of ametal material and the overcoat layer OC is weaker than the adhesionbetween the second insulating substrate 20 formed of a material such asglass and the overcoat layer OC. Therefore, in the proximity of thefirst terminals T1, the detachment of the overcoat layer OC mayadversely occur. Such detachment may occur when the flexible printedcircuit FPC2 needs to be peeled off in, for example, a manufacturing orrepairing process. Specifically, if a force is applied in the normaldirection of the second main surface 20B for peeling off the flexibleprinted circuit FPC2, the same force is applied to the overcoat layer OCby the adhesion of the anisotropy conductive layer ACF within theoverlap area OL. Since the adhesion between the first terminals T1 andthe overcoat layer OC is weak, the overcoat layer OC may possibly bedetached from the second main surface 20B or the first terminals T1 inthe proximity of the first terminals T1.

The problem of the detachment of the overcoat layer OC is caused byanother factor; the detection electrodes Rx formed on the outer surfaceof the liquid crystal display panel PNL (the second main surface 20B ofthe second insulating substrate 20). That is, the overcoat layer OC isformed by applying a resin material on the second main surface 20Bthrough an ink-jet (droplet ejection) print process and curing the resinmaterial thereon by heat treatment. In this heat treatment, thetemperature is kept below a certain level in consideration of a possibledamage to the liquid crystal layer LC or the like. The overcoat layer OCformed through the heat treatment of low temperature (approximately 120°C., for example) generally has a weaker adhesion to the second mainsurface 20B and the metal materials on the second main surface 20B ascompared to the overcoat layer OC formed by high-temperature heattreatment (at approximately 220° C., for example).

If the overcoat layer OC is prepared through the above print process,the ends of the overcoat layer OC may be formed irregularly in theproximity of the first terminals T1 due to a difference between thewettability of the overcoat layer OC and that of the second main surface20B and the metal materials.

FIG. 7 shows an example of the end shape irregularity of the overcoatlayer OC in which a plurality of the first terminals T1 and the overcoatlayer OC (projection R1 a) covering the first terminals T1 areillustrated in a plan view. A dotted line indicated near the end of theovercoat layer OC is a designed target limit TG used for positioning ofthe end of the overcoat layer OC. The resin material of the overcoatlayer OC is in a liquid state immediately after being applied to thesecond main surface 20B, and stops in the proximity of the target limitTG in the area where the first terminals T1 are not arranged. However,the resin material in a liquid state on the first terminals T1 flowstoward their tips over the target limit TG because of the highwettability of the metal materials. Therefore, the overcoat layer OCspreads on the first terminals T1 and the end shape becomes irregular.The irregularity may prevent an electrical connection between the firstterminals T1 and the second terminals T2.

In the present embodiment, the shape of the first terminal T1 is variedto prevent detachment and end shape irregularity of the overcoat layerOC. The shape of the first terminal T1 is now explained with referenceto FIG. 8. The first terminal T1 is patterned such that the metalmaterial thereof is partly removed from at least the part overlappingthe overlap area OL (hatched part).

From a different standpoint, an area of metal material of the firstterminal T1 per unit area in the overlap area OL (area arrangementratio) is smaller than that of the other area. The length of the firstterminal T1 in the second direction Y in the first area A1 is L1, thelength of the first terminal T1 in the second direction Y in the overlaparea OL is L2, and the length of the first terminal T1 in the seconddirection Y in the second area A2 is L3. The width of the first terminalT1 in the first direction X is W. Furthermore, the area of the metalmaterial of the first terminal T1 in the first area A1 is S1, the areaof the metal material of the first terminal T1 in the overlap area OL isS2, and the area of the metal material of the first terminal T1 in thesecond area A2 is S3. In that case, the area arrangement ratio isdefined as, for example, S1/(L1×W), S2/(L2×W), and S3/(L3×W) whereinS2/(L2×W)<S1/(L1×W), S3/(L3×W). If the width W is not constant, the areaarrangement ratio may be defined as S1/L1, S2/L2, and S3/L3. In thatcase, S2/L2<S1/L1, S3/L3.

If the above first terminal T1 is adopted, the contact area of theovercoat layer OC and the second main surface 20B which is firmlyadhesive to the overcoat layer OC can be increased within the overlaparea OL to which the detachment force is applied during peeling off ofthe flexible printed circuit FPC2. Consequently, the overcoat layer OCis not easily detached. Furthermore, the resin material of the overcoatlayer OC applied on the first terminals T1 is less fluid in the areawhere the metal material is partly removed since the contact areabetween the resin material and the metal material is reduced. Therefore,the end shape irregularity of the overcoat layer OC can be prevented.

Hereinafter, some variations of the shape of the first terminal T1 arepresented. In each example, the same or similar elements are referred toby the same reference number and redundant explanation is omitted.

First Example

FIG. 9 shows the shape of the first terminal T1 of the first example.The first terminal T1 includes a first part P1 which is covered with theovercoat layer OC and does not overlap the anisotropy conductive layerACF in a plan view, a second part P2 which is covered with theanisotropy conductive layer ACF and does not overlap the overcoat layerOC in a plan view, and a third part P3 which at least partly overlapsthe overlap area OL in a plan view and connects the first part P1 andthe second part P2. In the example of FIG. 9, the first part P1 is inthe first area A1, the second part P2 is in the second area A2, and thethird part P3 includes the first area A1, overlap area OL, and secondarea A2.

In the present example, the third part P3 has a line 30 whose width inthe first direction X is less than the first part P1, the second part P2and the lead LN3. In the example of FIG. 9, the first part P1 and thesecond part P2 have the same width which is greater than that of theline 30. The line 30 extends in the second direction Y and connects thefirst part P1 and the second part P2. The third part P3 having such aline 30 is an example of the above-described patterned structure.

The second part P2 has an opening 40 on the extension line of the line30. Furthermore, the second part P2 has notches 41 on both edges thereofin the first direction X. In the example of FIG. 9, two openings 40 andtwo notches 41 are formed successively in the second direction Y. Theopenings 40 and the notches 41 are to prevent the resin material of theovercoat layer OC from reaching the second part P2. That is, even if theresin material of the overcoat layer OC applied on the second mainsurface 20B flows toward the second part P2 along the line 30, theflowing resin material is trapped by the openings 40 formed on theextension line of the line 30 and the notches 41 at the both sides ofthe second part P2. Therefore, good conductivity can be secured betweenthe second part P2 and the flexible printed circuit FPC2.

The size of each of the first part P1, the second part P2, and thirdpart P3 should be determined based on factors such as tolerances of theovercoat layer OC and the anisotropy conductive layer ACF. For example,a tolerance of the edge of the overcoat layer OC is approximately ±0.1mm, a tolerance of the edge of the anisotropy conductive layer ACF isapproximately ±0.225 mm, a length La of the first part P1 in the seconddirection Y is approximately 0.2 mm, a length Lb between the boundary ofthe first part P1 and the third part P3 and the outer edge of theopenings 40 and the notches 41 in the second direction Y isapproximately 0.25 mm, and a length Lc between the outer edge of theopenings 40 and the notches 41 in the second direction Y and the end ofthe second part P2 in the second direction Y is approximately 0.6 mm.

Second Example

FIG. 10 shows a shape of the first terminal T1 of the second example.The first terminal T1 includes the first part P1, the second part P2,and the third part P3 as in the first example.

In this example, the third part P3 has two lines 31. In the example ofFIG. 10, the two lines 31 have the same width in the first direction Xwhich is less than the width of the lead LN3. The two lines 31 extend inthe second direction Y and connect the first part P1 and the second partP2. The third part P3 having such lines 31 is another example of theabove-described patterned structure.

The second part P2 has openings 40 formed on the extension lines of thelines 31. A plurality of the openings 40 may be formed in the seconddirection Y as in the example of FIG. 9.

If the two-line structure as in this example is adopted, the first partP1 and the second part P2 are connected through multiple paths, andconduction between the first part P1 and the second part P2 is securedeven if one of the lines 31 is cut for some reason.

In this example, the first part P1 and the second part P2 are connectedthrough two lines 31; however, the number of lines 31 is not limitedthereto. The first part P1 and the second part P2 may be connectedthrough three or more lines 31.

Third Example

FIG. 11 shows a shape of the first terminal T1 of the third example. Thefirst terminal T1 includes the first part P1, the second part P2, andthe third part P3 as in the first example.

In this example, the third part P3 has a line 32 bent several times. Inthe example of FIG. 11, the line 32 starts from the connection point inthe first part P1 extending in the second direction Y, then repeatsbending by approximately 90° several times, and finally extends in thesecond direction Y to reach the second part P2. The third part P3 havingsuch a line 32 is another example of the above described patternedstructure.

In the example of FIG. 11, the width of the line 32 is substantially thesame over its entirety and is less than the width of the lead LN3. Aconnection point C1 of the line 32 and the first part P1 and aconnection point C2 of the line 32 and the second part P2 are apart inthe first direction X.

The second part P2 has openings 40 on both the extension line of theline 32 extending from the connection point C1 in the second direction Yand the extension line of the line 32 extending to the connection pointC2 in the second direction Y. A plurality of the openings 40 may beformed more in the second direction Y as in the example of FIG. 9.

If the second part P2 includes a bending line 32 as in this example, theparts where the overcoat layer OC and the second main surface 20Bcontact with each other can be dispersed in the proximity of the overlaparea OL. Consequently, a possibility of detachment of the overcoat layerOC can further be decreased. Even if the resin material of the overcoatlayer OC flows in the second direction Y, the resin material is trappedby the bending line 32. Furthermore, even if the resin material flows onthe line 32, the flow can be stopped by the bent parts.

In this example, the line 32 bends by approximately 90°; however, theangle is not limited thereto. The line 32 may bend into an acute orobtuse angle. The line 32 may meander in arcs. The same advantage can beachieved in this case.

Fourth Example

FIG. 12 shows a shape of the first terminal T1 of the fourth example.The first terminal T1 includes the first part P1, the second part P2,and the third part P3 as in the first example.

In this example, the third part P3 has a plurality of lines 33 extendingin the first direction X and a plurality of connectors 34. Theconnectors 34 are arranged between adjacent lines 33 for the connection.Furthermore, the connectors 34 are arranged between the first part P1and the nearest line to the first part P1 and between the second part P2and the nearest line to the second part P2 for the connection. The thirdpart P3 having such lines 33 and connectors 34 is another example of theabove-described patterned structure.

In the example of FIG. 12, the width of the line 33 in the seconddirection Y and the width of the connector 34 in the first direction Xare less than the width of the lead LN3.

If the resin material of the overcoat layer OC is applied by the ink-jetapplication process, some areas surrounded by the lines 33 andconnectors 34 may be missed and such areas do not include an overcoatlayer OC. Therefore, the size of and gap between the lines 33 and theconnectors 34 may be determined such that the areas surrounded by thelines 33 and connectors 34 become smaller than a pitch (resolution) of adroplet of the resin material sprayed from a head of an ink-jet device.For example, the pitch may be set to approximately 70 μm in both thefirst direction X and the second direction Y.

In the example of FIG. 12, the number of the connectors 34 connected toa long side of a line 33 at the first part P1 side is different fromthat at the second part P2 side (one and two connectors 34 are connectedto the sides alternately). Furthermore, the connectors 34 connected to along side of a line 33 at the first part P1 side are positioned to beshifted in the first direction X from the connectors 34 connected to along side of the line 33 at the second part P2 side.

The second part P2 has an opening 40 in the proximity of each connectionpoint of the connector 34 and the second part P2. A plurality of theopenings 40 may be formed in the second direction Y as in the example ofFIG. 9.

If the third part P3 is defined by the lines 33 and the connectors 34 asin this example, the parts where the overcoat layer OC and the secondmain surface 20B contact with each other can be dispersed in theproximity of the overlap area OL. Consequently, a possibility ofdetachment of the overcoat layer OC can further be decreased. Even ifthe resin material of the overcoat layer OC flows in the seconddirection Y, the resin material is trapped by the openings defined bythe lines 33 and the connectors 34. Furthermore, even if the resinmaterial flows on the lines 33 and the connectors 34, the flow can bestopped because the positions of the connectors 34 are not continuous inthe second direction Y.

Fifth Example

FIG. 13 shows a shape of the first terminal T1 of the fifth example. Thefirst terminal T1 includes a first part P1, second part P2, and thirdpart P3 as in the first example.

In this example, the third part P3 has a plurality of first lines 35 anda plurality of second lines 36 crossing the first lines 35. The firstlines 35 and the second lines 36 extend in a direction crossing both thefirst direction X and the second direction Y. The first lines 35 and thesecond lines 36 are connected to the first part P1, the second part P2,or both of them. The third part P3 having such first lines 35 and secondlines 36 is another example of the above-described patterned structure.

In the example of FIG. 13, the width of the first line 35 and the widthof the second line 36 are less than the width of the lead LN3.

The second part P2 has an opening 40 in the proximity of each connectionpoint of both the first and second lines 35 and 36 and the second partP2. A plurality of the openings 40 may be formed more in the seconddirection Y as in the example of FIG. 9.

If the third part P3 is defined by the first line 35 and the secondlines 36 as in this example, the parts where the overcoat layer OC andthe second main surface 20B contact with each other can be dispersed inthe proximity of the overlap area OL. Consequently, a possibility ofdetachment of the overcoat layer OC can further be decreased. Even ifthe resin material of the overcoat layer OC flows in the seconddirection Y, the resin material is trapped by the openings defined bythe first lines 35 and the second lines 36. Furthermore, since the firstpart P1 and the second part P2 are connected through multiple paths,conduction between the first part P1 and the second part P2 is securedeven if one of the lines 35 and 36 is cut for some reason.

Sixth Example

FIG. 14 shows a shape of the first terminal T1 of the sixth example. Thefirst terminal T1 includes a first part P1, second part P2, and thirdpart P3 as in the first example.

In this example, the third part P3 has slits 37, 38, and 39. Each of theslits 37 and 38 is formed in an arc shape. The slit 39 is a combinationof two semicircular slits arranged in the first direction X. The thirdpart P3 having such slits 37, 38, and 39 is another example of theabove-described patterned structure.

In the example of FIG. 14, the width of the slits 37, 38, and 39 is lessthan the width of the lead LN3.

The second part P2 has an opening 40 in the proximity of the centerthereof in the first direction X. A plurality of the openings 40 may beformed more in the second direction Y as in the example of FIG. 9.

Even if the third part P3 includes slits 37, 38, and 39 as in thisexample, the area arrangement ratio of the metal material in the overlaparea OL can be made small and the detachment of the overcoat layer OCcan be prevented. Furthermore, even if the resin material of theovercoat layer OC flows in the second direction Y, the resin material istrapped by the slits 37, 38, and 39. In this example, the slits 37, 38,and 39 are formed in arc-like shapes, and the resin material is smoothlyguided in different directions by the slits 37, 38, and 39.Consequently, the resin material hardly reaches the second part P2.

With respect to the first terminal T1 of the first example, theinventors of the present application assessed a suitable width of theline 30 for prevention of the end shape irregularity of the overcoatlayer OC. FIG. 15 shows an outline of the assessment. In thisassessment, leads LN 3 and first terminals T1 were formed on a glasssubstrate, and an overcoat layer OC was formed thereon to measure alength LX1 of the overcoat layer OC projecting on the lines 30. Width W1of the lead LN3 and width W2 of the line 30 were changed to obtain aplurality of examples.

FIG. 16 is a table showing a result of the measurement of the lengthLX1. The length LX1 was measured where width W1 of the lead LN3 was 100μm and width W2 of the line 30 was changed in seven ways: 120, 105, 95,50, 25, 18, and 10 μm. In these seven examples, the measured length LX1was approximately 92, 85, 52, 30, 18, 2, and 1 μm, respectively.Furthermore, the length LX1 was measured where width W1 of the lead LN3was 50 μm and width W2 of the line 30 was changed in seven ways: 60, 50,40, 30, 20, 10, and 5 μm. In these seven examples, the measured lengthLX1 was approximately 71, 25, 19, 16, 12, 3, and 1 μm, respectively. Theresult indicates that the length LX1 decreases when width W2 of the line30 decreases. Especially, if width W1 is 100 μm, the length LX1 steeplydecreases when width W2 is decreased from 105 to 95 μm, and if width W1is 50 μm, the length LX1 steeply decreases when width W2 is decreasedfrom 60 to 50 μm. Therefore, by setting width W2 substantially the sameas or less than width W1, the end shape irregularity of the overcoatlayer OC can be greatly reduced.

Furthermore, if width W2 is less than approximately one fifth width W1(W2/W1≦⅕), the length LX1 becomes significantly small. Therefore, bysetting width W2 to a value satisfying this condition, the end shapeirregularity of the overcoat layer OC can further be reduced.

With respect to the first terminal T1 of the fourth example, theinventors of the present application also performed the assessment inthe same manner. FIG. 17 shows an outline of the assessment. In thisassessment, the leads LN 3 and the first terminals T1 were formed on aglass substrate, and an overcoat layer OC was formed thereon to measurea length LX2 of the overcoat layer OC projecting on the connectors 34.Width W1 of the lead LN3 and width W3 of the connector 34 were changedto obtain a plurality of examples.

FIG. 18 is a table showing a result of the measurement of the lengthLX2. The length LX2 was measured where width W1 of the lead LN3 was 120μm and width W3 of the connector 34 was changed in seven ways: 125, 115,90, 50, 30, 15, and 10 μm. In these seven examples, the measured lengthLX2 was approximately 89, 65, 40, 29, 7, 1, and 0 μm, respectively.Furthermore, the length LX2 was measured where width W1 of the lead LN3was 60 μm and width W3 of the connector 34 was changed in seven ways:65, 55, 40, 30, 20, 10, and 5 μm. In these seven examples, the measuredlength LX2 was approximately 59, 24, 21, 20, 9, 1, and 0 μm,respectively. The result indicates that the length LX2 decreases whenwidth W3 of the connector 34 decreases. Especially, if width W1 is 120μm, the length LX2 steeply decreases when width W3 is decreased from 125to 115 μm, and if width W1 is 60 μm, the length LX2 steeply decreaseswhen width W3 is decreased from 65 to 55 μm. Therefore, by setting widthW3 substantially the same as or less than width W1, the end shapeirregularity of the overcoat layer OC can be greatly reduced.

Furthermore, if width W3 is less than approximately one fifth width W1(W3/W1≦⅕), the length LX2 becomes significantly small. Therefore, bysetting width W3 to a value satisfying this condition, the end shapeirregularity of the overcoat layer OC can further be reduced.

Note that, with respect to the lines 31 of the second example, the lines32 of the third example, and the first and second lines 35 and 36 of thefifth example, by setting the width of these lines to substantially thesame as or less than width W1 of the lead LN3, the end shapeirregularity of the overcoat layer OC can suitably be reduced.

The structure of the embodiment described above can be varied suitably.For example, the shape of the first terminal T1 is not limited to thatof the first to sixth examples. Lines, slits, or combinations of linesand slits formed in various shapes can be used for the third part P3.

In the present embodiment, the sensor SE performs sensing using bothdetection electrodes and driving electrodes (referred to as a mutualcapacitance detection method, or the like); however, the sensor may beof different kinds. For example, the sensor SE may perform sensing usingthe capacitance of the detection electrodes (referred to as a selfcapacitance detection method, or the like).

Furthermore, in the present embodiment, only the detection electrodesare disposed on the second main surface 20B of the second substrateSUB2. However, not only the detection electrodes, driving electrodes mayalso be disposed on the second main surface 20B of the second substrateSUB2. In that case, with respect to the first terminals T1 formed in theframe area FA, some terminals T1 are connected to the detectionelectrodes and the other terminals T1 are connected to the drivingelectrodes.

In the self capacitance detection method, sensor driving signals aresupplied to each of the detection electrodes Rx and sensor outputsignals are read from each of the detection electrodes Rx. An objectcontacting or approaching the display area DA influences the capacitanceof the detection electrodes Rx, and thus, the position of the object inthe arrangement direction of the detection electrodes Rx can be detectedbased on the sensor output signals obtained from the detectionelectrodes Rx. The detection electrodes Rx may be formed in a matrixextending both the first direction X and the second direction Y in thedisplay area DA. In that case, the position of the object can bedetected two-dimensionally in the first direction X and the seconddirection Y.

In the present embodiment, the sensor SE is a so-called in-cell sensorwhich uses the common electrodes CE of the liquid crystal display panelPNL. However, the sensor SE may include, separately from the commonelectrodes CE, driving electrodes and detection electrodes Rx disposedoutside the liquid crystal display panel PNL. In that case, the drivingelectrodes and the detection electrodes Rx may be disposed to be opposedto each other with the insulating layer interposed therebetween, or maybe disposed alternately on the same layer.

In the present embodiment, the detection electrode Rx and the lead LN3are formed of a metal material as with the first terminal T1. However,either the detection electrode Rx or the lead LN3, or both may be formedof a transparent conductive material such as ITO. Furthermore, the leadLN3 and the first terminal T1 may be formed of a layered structure of atransparent conductive material such as ITO and a metal material.

While certain embodiments have been described, these embodiments havebeen presented by way of example only, and are not intended to limit thescope of the inventions. Indeed, the novel embodiments described hereinmay be embodied in a variety of other forms; furthermore, variousomissions, substitutions and changes in the form of the embodimentsdescribed herein may be made without departing from the spirit of theinventions. The accompanying claims and their equivalents are intendedto cover such forms or modifications as would fall within the scope andspirit of the inventions.

EXPLANATION OF REFERENCES

DSP: Liquid crystal display device; PNL: Liquid crystal display panel;SE: Sensor; Rx: Detection electrode; DA: Display area; LC: liquidcrystal layer; CE: Common electrode; OC: Overcoat layer; RC: Detectioncircuit; T1: First terminal; T2: Second terminal; ACF: Anisotropyconductive layer; OL: Overlap area; A1: First area; A2: Second area; P1:First part; P2: Second part; P3: Third part; FPC2: flexible printedcircuit; LN3: lead; 20: Second insulating substrate; 30: line; 40:Opening.

The invention claimed is:
 1. A detection device, comprising: asubstrate; a detection electrode formed on a main surface of thesubstrate, the detection electrode used for detection of an objectcontacting or approaching the substrate; a terminal formed of a metalmaterial on the main surface of the substrate; a lead formed on the mainsurface of the substrate, the lead electrically connecting the detectionelectrode and the terminal; a coating layer covering the detectionelectrode, the lead, and a part of the terminal; a conductive adhesionlayer covering a part of the terminal exposed from the coating layer,the conductive adhesion layer covering a part of the coating layer; anda circuit board electrically connected to the terminal with theconductive adhesion layer interposed therebetween, wherein at least inan overlapping area where the conductive adhesion layer covers thecoating layer, an area of the metal material of the terminal per unitarea is smaller than that of the other area of the terminal.
 2. Thedetection device of claim 1, wherein the terminal is formed such thatthe metal material is partly removed therefrom at least in theoverlapping area.
 3. The detection device of claim 1, wherein theterminal includes a line in the overlapping area, the line having asecond width which is less than a first width of the lead.
 4. Thedetection device of claim 3, wherein the line meanders or bends.
 5. Thedetection device of claim 3, wherein the terminal includes a pluralityof the lines crossing each other.
 6. The detection device of claim 1,wherein the terminal comprises: a plurality of lines extending in afirst direction and arranged at intervals in a second direction crossingthe first direction; and a connector disposed in each gap between thelines for connection thereof.
 7. The detection device of claim 6,wherein the connector has a third width which is less than a first widthof the lead.
 8. The detection device of claim 1, wherein the terminalincludes a slit in the overlapping area.
 9. The detection device ofclaim 3, wherein the terminal comprises: a first part covered with thecoating layer; a second part covered with the conductive adhesion layer;and a third part including the line, the third part at least partlyoverlapping with the overlapping area and connecting the first part andthe second part.
 10. The detection device of claim 9, wherein the secondpart has an opening on an extension line of the line.
 11. A displaydevice with a detection function, comprising: a display panel includinga display element, a plurality of first electrodes disposed inrespective pixels in a display area, and a second electrode opposed tothe first electrodes, the display panel configured to display an imagein the display area by selectively applying a voltage between the firstelectrode and the second electrode to drive the display element; adetection electrode formed on an outer surface of the display panel, thedetection electrode used for detection of an object contacting orapproaching the display area; a terminal formed of a metal material onthe outer surface of the display panel; a lead formed on the outersurface of the display panel, the lead electrically connecting thedetection electrode and the terminal; a coating layer covering thedetection electrode, the lead, and a part of the terminal; a conductiveadhesion layer covering a part of the terminal exposed from the coatinglayer and covering a part of the coating layer; a circuit boardelectrically connected to the terminal with the conductive adhesionlayer interposed therebetween; and a detection circuit configured todetect the object based on a second signal output from the detectionelectrode to the circuit board through the lead and the terminal when afirst signal for detection of the object is supplied to the secondelectrode, wherein at least in an overlapping area where the conductiveadhesion layer covers the coating layer, an area of the metal materialof the terminal per unit area is smaller than that of the other area ofthe terminal.
 12. The display device of claim 11, wherein the terminalis formed such that the metal material is partly removed therefrom atleast in the overlapping area.
 13. The display device of claim 11,wherein the terminal includes a line in the overlapping area, the linehaving a second width which is less than a first width of the lead. 14.The display device of claim 13, wherein the line meanders or bends. 15.The display device of claim 13, wherein the terminal includes aplurality of the lines crossing each other.
 16. The display device ofclaim 11, wherein the terminal comprises: a plurality of lines extendingin a first direction and arranged at intervals in a second directioncrossing the first direction; and a connector disposed in each gapbetween the lines for connection thereof.
 17. The display device ofclaim 16, wherein the connector has a third which is less than a firstwidth of the lead.
 18. The display device of claim 11, wherein theterminal includes a slit in the overlapping area.
 19. The display deviceof claim 13, wherein the terminal comprises: a first part covered withthe coating layer; a second part covered with the conductive adhesionlayer; and a third part including the line, the third part at leastpartly overlapping with the overlapping area and connecting the firstpart and the second part.
 20. The display device of claim 19, whereinthe second part has an opening on an extension line of the line.